Target put out three novelisations of stories that were commissioned for the cancelled series 23 of which this is the only one by an unknown writer/producer and not featuring an returning villain. Wally K. Daly has a minimal wikipedia entry which nevertheless suggests he was an interesting writer of Radio plays. I recall almost nothing about the book beyond it was the weakest of the three stories (all of which were weak, suggesting somewhat that they were quickly written up from half-finished ideas or at least early drafts rather than adapted from completed scripts) and that the alien villain seemed to be something of a duplicate of the popular Sil character from the previous season (and who appeared in the third of these novelisations).

I remember this being weak too, although I also don't recall the details. You are right that the three novelisations were all poor, including a terribly sexist matriarchy story (featuring the Ice Warriors, Sil and a(nother) rogue Time Lord because it was the eighties). I think Big Finish still adapted them all, though!